A real-time chat application needs persistent two-way communication between clients and backend — messages pushed in both directions without polling. Which API Gateway type should be used?
A.REST API
REST APIs are request-response; servers can't push to clients.
B.HTTP API
HTTP APIs are also request-response (simpler/cheaper REST).
C.WebSocket API
Correct. WebSocket APIs provide persistent bidirectional channels.
D.Private API
Private refers to VPC access scope, not communication pattern.
Why this answer
API Gateway WebSocket APIs maintain persistent connections enabling true bidirectional push — the right choice for chat/live-update apps. REST and HTTP APIs are request-response only.
Correct answer: C · Last reviewed 2026-10-26
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